Field of the Invention
The present invention relates to an image pickup apparatus including a focus operating apparatus and a focus control method for the image pickup apparatus, and more particularly, to an image pickup apparatus including a lens apparatus having an autofocus (AF) function and a focus operating apparatus (focus demand) for operating the lens apparatus, and to a focus control method for the image pickup apparatus.
Description of the Related Art
Conventionally, as a focus operating apparatus for operating a focus lens of a lens apparatus, there has been used an apparatus in which an operating end has a limited operable rotation range and is capable of outputting a proportional command signal within the rotation range (non-endless operating apparatus), or an apparatus provided with an operating end of a type for outputting a command value corresponding to a relative operation amount (rotation amount) with its rotation range not limited (endless operating apparatus). Technologies related to an image pickup apparatus including the endless operating apparatus (endless focus demand) are described in Japanese Patent No. 3785991 and Japanese Patent Application Laid-Open No. 2007-094133.
In Japanese Patent No. 3785991, it is determined whether the endless operating apparatus or the non-endless operating apparatus is connected to a lens apparatus, and when the endless operating apparatus is connected to the lens apparatus, the lens apparatus converts a relative value into an absolute value.
In Japanese Patent Application Laid-Open No. 2007-094133, when a rotation count of the endless operating apparatus reaches a predetermined rotation count, a reset signal is output from a photo interpreter provided in the endless operating apparatus, then a lens is driven to a predetermined position to maintain the correspondence relationship between the rotation position of the endless operating apparatus and the position of the lens.
In a general operating apparatus used for the lens apparatus having the AF function, an AF mode is shifted to a manual mode by manual operation of an operating portion during control in the AF mode. When the manual operation is stopped, the manual mode is returned to the AF mode. Such a switching timing is determined by monitoring a change in command value which is caused by the manual operation. That is, when the command value does not change, it is determined that the manual operation is not performed. However, in a case where the operating portion is of an endless type, when the manual operation is performed beyond a command end point, a fixed end position command is output. When the fixed end position command continues to be output, it is determined that the manual operation is not performed even in the case where the manual operation is performing. Therefore, the control mode is returned to the AF mode. As a result, the operability of the operating portion is not common between the end range and another range.
Japanese Patent No. 3785991 discloses only the point that, when the operating portion included in the endless operating apparatus continues to be rotated, a command fixed to an upper limit value or a lower limit value is generated in the lens apparatus. Therefore, in a case where the endless operating apparatus is used for an AF lens, when the manual operation is performed out of a driving range, there is a possibility that the control mode is shifted to the AF mode at an unintended timing for a photographer.
Japanese Patent Application Laid-Open No. 2007-094133 discloses only the point that, when the relative position of the endless operating apparatus and the absolute position of the lens are deviated from each other, the operating portion is returned to a reference position to perform position correction.